1 files changed, 125 insertions, 0 deletions
diff --git a/gearboy/src/CommonMemoryRule.h b/gearboy/src/CommonMemoryRule.h
new file mode 100644
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+++ b/gearboy/src/CommonMemoryRule.h
@@ -0,0 +1,125 @@
+/*
+ * Gearboy - Nintendo Game Boy Emulator
+ * Copyright (C) 2012  Ignacio Sanchez
+
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * any later version.
+
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see http://www.gnu.org/licenses/
+ *
+ */
+
+#ifndef COMMONMEMORYRULE_H
+#define	COMMONMEMORYRULE_H
+
+#include "definitions.h"
+
+class Memory;
+
+class CommonMemoryRule
+{
+public:
+    CommonMemoryRule(Memory* pMemory);
+    ~CommonMemoryRule();
+    u8 PerformRead(u16 address);
+    void PerformWrite(u16 address, u8 value);
+    void Reset(bool bCGB);
+
+private:
+    Memory* m_pMemory;
+    bool m_bCGB;
+};
+
+#include "Memory.h"
+
+inline u8 CommonMemoryRule::PerformRead(u16 address)
+{
+    if (m_bCGB)
+    {
+        switch (address & 0xE000)
+        {
+            case 0x8000:
+            {
+                return m_pMemory->ReadCGBLCDRAM(address, false);
+            }
+            case 0xC000:
+            {
+                return m_pMemory->ReadCGBWRAM(address);
+            }
+        }
+    }
+    else if (address >= 0xFEA0 && address < 0xFF00)
+    {
+        return ((((address + ((address >> 4) - 0x0FEA)) >> 2) & 1) ? 0x00 : 0xFF);
+    }
+
+    return m_pMemory->Retrieve(address);
+}
+
+inline void CommonMemoryRule::PerformWrite(u16 address, u8 value)
+{
+    switch (address & 0xE000)
+    {
+        case 0x8000:
+        {
+            if (m_bCGB)
+                m_pMemory->WriteCGBLCDRAM(address, value);
+            else
+                m_pMemory->Load(address, value);
+            break;
+        }
+        case 0xC000:
+        {
+            if (address < 0xDE00)
+            {
+                if (m_bCGB)
+                    m_pMemory->WriteCGBWRAM(address, value);
+                else
+                    m_pMemory->Load(address, value);
+
+                m_pMemory->Load(address + 0x2000, value);
+            }
+            else if (m_bCGB)
+            {
+                m_pMemory->WriteCGBWRAM(address, value);
+            }
+            else
+            {
+                m_pMemory->Load(address, value);
+            }
+            break;
+        }
+        case 0xE000:
+        {
+            if (address < 0xFE00)
+            {
+                if (m_bCGB)
+                    m_pMemory->WriteCGBWRAM(address - 0x2000, value);
+                else
+                    m_pMemory->Load(address - 0x2000, value);
+
+                m_pMemory->Load(address, value);
+            }
+            else
+            {
+                m_pMemory->Load(address, value);
+            }
+            break;
+        }
+        default:
+        {
+            Log("--> ** Writing to invalid area %X %X", address, value);
+            m_pMemory->Load(address, value);
+        }
+    }
+}
+
+#endif	/* COMMONMEMORYRULE_H */